1. Field of the Invention
The present invention relates to a metal complex using a copper group metal, and more specifically, to a polymeric mixed-metal complex containing plural metals out of copper, silver, and gold. In addition, the present invention relates to a light emitting device using the polymeric mixed-metal complex as a light emitting material.
2. Description of the Related Art
Conventional examples of a polymeric complex using a copper group metal include copper polymeric complexes listed in “Luminescence Ranging from Red to Blue: A Series of Copper(I)-Halide Complexes Having Rhombic {Cu2(μ-X)2} (X=Br and I) Units with N-Heteroaromatic Ligands (Araki, H.; Tsuge, K.; Sasaki, Y.; Ishizaka, S.; Kitamura, N Inorg. Chem.; (Article); 2005; 44 (26); 9667-9675.)”. Specific examples of such copper polymeric complexes include those each having a structural formula shown in the following formula (10).

A polymeric metal complex described in the above document emits light in a visible light region, and its luminescent color can be selected by properly selecting a ligand. However, the complex uses only copper as a metal.
Meanwhile, “Proceedings 3F1-14 of the 86th spring annual meeting of the Chemical Society of Japan (2006) “Synthesis and light emitting property of each of gold(I)-silver(I) mixed-metal complex and copper(I)-silver(I) mixed-metal complex each using dimercaptothiadiazole as crosslinking ligand” by Motoshi Tamura, Kota Suzuki, Kiyoshi Tsuge, Yoichi Sasaki, Shoji Ishizaka, and Noboru Kitamura” describe a polymeric mixed-metal complex represented by the following structural formula.

The above document describes that the mixed-metal complex is synthesized by selecting two kinds from Cu, Ag, and Au as M, and describe the light emitting property of the mixed-metal complex.
However, none of the documents describes the application of each of those complexes to a light emitting material for use in a light emitting device, and the contents of the documents are limited to researches on the molecular structures and photophysical properties of the complexes.